JPH0664839B2 - Disk playback device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a disk reproducing device which can be suitably implemented in a compact disk reproducing device mounted on a vehicle.

BACKGROUND ART Compact discs have been remarkably popularized in recent years due to their good sound quality and low cost due to mass production effects. Since this compact disk is resistant to scratches and dust and has good vibration resistance and temperature resistance, it is also suitable for use in vehicles.

On the other hand, it has been proposed to use the compact disk as an external recording medium of a computer, that is, a so-called CDROM, from the viewpoint of its recording capacity and reading speed.
For example, in a so-called navigation system which has been put into practical use in recent years, it is very effective to use it for recording a huge amount of geographical data and the like for the above reason.

For this reason, a navigation system can be made relatively inexpensive by connecting a decoder for the navigation system as an additional device to the vehicle-mounted compact disc player and sharing the drive system and the signal reading system of the compact disc player. Can be realized.

Therefore, FIG. 3 shows a disk reproducing device 25 having both the function of performing such normal sound reproduction that can be simply considered and the function of DCROM. In the compact disc player 26, the signal recorded on the compact disc 1 is read by the optical head 2, amplified by the amplifying circuit 3, shaped by the waveform shaping circuit 6, and derived as a so-called EFM signal. This EFM signal is given to the demodulation circuit 7 and the clock reproduction circuit 8. The reproduction clock signal reproduced by the clock reproduction circuit 8 is applied to the demodulation circuit 7, the jitter absorption circuit 12 and a phase-locked loop (abbreviated as PLL) circuit 9 described later.
As a result, a 16-bit demodulated signal is derived from the demodulation circuit 7, the time axis is corrected in the jitter absorption circuit 12 based on the clock signal transmitted through the line 21, and the error correction circuit 13 performs error correction. It is given to the discrimination circuit 14.

The discrimination circuit 14 discriminates whether the input circuit is a data signal as a CDROM, that is, a navigation system data signal or an acoustic signal. When the input signal is an acoustic signal, it is given to the interpolation circuit 15 to interpolate the data, and the channel separation circuit 16
The left and right channels are separated in. The data of the acoustic signals of the left and right channels thus obtained are given to the digital / analog conversion circuits 17a, 17b and converted into analog signals, the noise components are removed in the low-pass filters 18a, 18b, and they are derived to the amplification circuits 19a, 19b. It Amplifier circuit 19a, 1
The acoustic signal from 9b is given to the speakers 20a and 20b and is emitted as the sound of each of the left and right channels.

The reproduction clock signal reproduced by the clock reproduction circuit 8 is
The synchronization is detected by the PLL circuit 9, the motor 11 is controlled via the drive circuit 10 based on the detection result, and the rotation speed of the compact disk 1 is kept constant. The deviation of the optical head 2 is detected by the signal from the amplifier circuit 3 being given to the error detection circuit 4, and the deviation of the optical head 2 is corrected by the drive circuit 5 based on the detection result.

When the discriminating circuit 14 discriminates that the input signal is the data signal for the navigation system, it is given to the data processing circuit 22 of the decoder 27 and based on the reproduced clock signal from the clock reproducing circuit 8 through the line 8a. Map data is created by using the map data and is given to the display device.

The output of the discrimination circuit 14 is also given to the control circuit 28,
When data is being transferred from the discriminating circuit 14 to the data processing circuit 22, the control circuit 28 gives the RE signal indicating the data transfer to the control circuit 30 of the decoder 27 via the line 23. The control circuit 30 gives a control signal for reading desired map data to the control circuit 28 via the line 24.
According to this control signal, the control circuit 28 designates the address and the like of the compact disk 1 by a configuration not shown. An input circuit 29 is provided in association with the control circuit 28, and in accordance with the input operation, the order of reproduced music when reproducing an audio signal is controlled.

Problems to be Solved by the Invention In such a prior art, the demodulation circuit 7, the jitter absorption circuit 12, the error correction circuit 13, the determination circuit 14, and the interpolation circuit 15
Is integrally formed as an integrated circuit. In the integrated circuit, the discriminating circuit 14 occupies a large cost, and therefore, the cost is significantly increased in comparison with an integrated circuit which does not include the discriminating circuit 14 used in such a compact disc reproducing-only machine having no CDROM function. To do. In addition, in the navigation system, the error correction circuit 13 is required to have a strong correction capability, and this also increases the cost of the integrated circuit.

On the other hand, there is very little possibility that the navigation system will be widespread with respect to the number of compact disc quillers sold. Therefore, the compact disc player is equipped with the expensive discriminating circuit 14 as a standard equipment.
Installing it on the 26 will put a futile burden on the majority of users.

The object of the present invention is to provide a discriminating means for discriminating whether a signal read from a disk is a data signal or at least one of a video signal and an audio signal in the data processing section. To provide a disc reproducing apparatus with a low cost, in which the structure of the video / audio reproducing unit is simplified and a discriminating means is provided only when a data processing unit is added to the video / audio reproducing unit. Is.

Means for Solving the Problems The present invention is a discriminating means for discriminating whether a signal read from a disk is a data signal or at least one of a video signal and an audio signal, and a signal from the disk. And a video / sound reproduction unit that reproduces at least one of the video signal and the audio signal based on the output from the determination unit, and the processing of the data signal based on the output from the determination unit. A disc reproducing apparatus including a data processing section for performing the disc reproducing apparatus, wherein the discriminating means is provided in the data processing section.

Operation According to the invention, the discriminator determines whether the signal read from the disk is a data signal or at least one of a video signal and an audio signal, and the video signal or the audio signal is detected. If this is the case, this signal is given to the video / audio reproduction unit and reproduced as video and / or audio. When the signal read from the disk is a data signal, that is, the disk is, for example, CDRO
When used as M, this signal is given from the discriminating means to the data processing section, and predetermined data processing is performed.

The discriminating means is provided in the data processing section. Therefore, when the discriminating means is used only in the video / audio reproducing section, the discriminating means is not included in the video / audio reproducing section. The cost can be kept low.

Embodiment FIG. 1 is a block diagram showing the basic structure of a disk reproducing apparatus 31 according to an embodiment of the present invention. The audio signal reproduced by the compact disk player 32, which is a video / audio reproducing unit, is given to the amplifier circuits 34a and 34b via the line 33, amplified, and emitted as sound from the speakers 35a and 35b. A amplifying circuit 34a, 34b is also provided with a muting signal from the compact disk player 32 via line 36.

In the compact disc player 32, the EFM signal read from the compact disc 51 is given to a decoder 38 which is a data processing unit via a line 37. This decoder 38 also indicates that data is being transferred from the compact disk player 32 via line 39.
RE signal is given. The decoder 38 is provided with a discriminating circuit 64, and the EFM signal described above is given to the discriminating circuit 64 to discriminate whether it is a sound signal or a data signal for a navigation system. The result of the determination is given to the control circuit 80, derived as a control signal on the line 40 together with other control information, and given to the compact disc player 32. In this way, the discrimination circuit 64
When it is determined that the EFM signal is the data signal, the compact disc player 32 is operated in response to the control signal.
Derives a muting signal to the amplifier circuits 34a, 34b via the line 36, and the amplifier circuits 34a, 34b perform a muting operation.

When the EFM signal is a data signal, the discriminating circuit 64 also converts it into map data and supplies it to the display control circuit 42 via the line 41. In relation to the display control circuit 42, a key input device 43 for inputting the current position or an area where the map is desired to be read out, and a geomagnetic detector 44 for detecting the traveling direction and distance of the vehicle body are provided. An image in which the current location is represented by the position signal from the geomagnetic detector 44 is provided on the map designated by the key input device 43, and the image is realized by, for example, a cathode ray tube. Displayed on the device 45, a so-called navigation system is realized.
The display control circuit 42 gives a control signal for reading out the map data designated by the key input device 43 to the decoder 38 via the line 46.

FIG. 2 is a block diagram showing a specific configuration of the disk reproducing device 31. In the compact disc player 32, the signal recorded on the compact disc 51 is read by the optical head 52, amplified by the amplifier circuit 53, shaped by the waveform shaping circuit 56, and derived as a so-called EFM signal. This EFM signal is given to the demodulation circuit 57 and the clock reproduction circuit 58. The reproduction clock signal reproduced by the clock reproduction circuit 58 is supplied to the demodulation circuit 57 and the jitter absorption circuit 62.
And a PLL circuit 59 described later. As a result, the 16-bit demodulated signal is derived from the demodulation circuit 57, time-axis corrected in the jitter absorption circuit 62 based on the clock signal via the line 69, and error correction is performed in the error correction circuit 63 to interpolate. Given to circuit 65.

The interpolation circuit 65 interpolates the data, and the channel separation circuit 66 separates the left and right channels. The data of the acoustic signals of the left and right channels thus obtained are given to the digital / analog conversion circuits 67a, 67b for analog conversion, the noise components are removed in the low pass filters 68a, 68b, and the data are derived to the amplification circuits 34a, 34b. It The acoustic signals from the amplifier circuits 34a, 34b are given to the speakers 35a, 35b and emitted as the sounds of the left and right channels.

The reproduction clock signal reproduced by the clock reproduction circuit 58 is
Synchronization is detected by the PLL circuit 59, the motor 61 is controlled via the drive circuit 60 based on the detection result, and the rotation speed of the compact disk 51 is kept constant. If the optical head 52 is out of alignment, the signal from the amplifier circuit 53 is
The optical head 52 is corrected by the drive circuit 55 based on the detection result given to the optical head 54.

The EFM signal from the waveform shaping circuit 56 is also given to the discrimination circuit 64 of the decoder 38 via the line 37. This discrimination circuit
64 determines, as described above, whether the EFM signal is an acoustic signal or a data signal, and when it is a data signal, derives a control signal from the control circuit 80 to the control circuit 70 of the compact disk player 32, The amplifier circuits 34a and 34b perform a muting operation. When the EFM signal is a sound signal, the compact disc player 32 does not derive a control signal for performing a muting operation, whereby normal sound reproduction is performed. The control circuit 70 also
According to a control signal from the control circuit 80, an address or the like of the compact disk 51 is designated by a configuration not shown. An input circuit 71 is provided in association with the control circuit 70, and the order of reproduction songs at the time of reproducing an audio signal is controlled according to the input operation.

When the EFM signal is a data signal, the discrimination circuit 64 guides this data signal to the demodulation circuit 81 and the clock reproduction circuit 88, and demodulates it into a 16-bit data signal. The demodulated data signal is time-axis corrected by the jitter absorption circuit 82, the error is corrected by the error correction circuit 83, and the data processing circuit 84
Given to. The data processing circuit 84 creates map data from the data signal. The map data thus created is given to the display control circuit 42 via the line 41 as described above. In this way, the function as a so-called CDROM is realized.

In the disk reproducing device 31 having such a configuration, the compact disk player 32 can be used as a normal compact disk player which reproduces the sound of the compact disk 51 by itself. Further, by adding the decoder 38 having the discriminating circuit 64, it is possible to reproduce the compact disc in which the map data for the navigation system is recorded. Thus, by sharing the compact disk player 32 for normal sound signal reproduction and reproduction of the data signal of the navigation system, the navigation system can be realized at a relatively low cost.

Further, since the discriminator circuit 64 for discriminating whether the reproduced EFM signal is an audio signal or a data signal is provided in the decoder 38, the compact disc player 32 is not used in a general navigation system. The configuration is almost the same as that of the compact disc player dedicated to reproduction of audio signals, and thus the compact disc player 32 that can be expanded to the navigation system can be realized at low cost.

Furthermore, EF given to the discrimination circuit 64 via the line 37
The M signal contains the reproduction clock component, and therefore the line 8a for the reproduction clock signal, which is required in the disk reproducing device 25 of the prior art, can be deleted, and the connection is simple.

As described above, according to the present invention, the data processing unit is provided with a discriminating means for discriminating whether the signal read from the disk is a data signal or at least one of a video signal and an audio signal. Since the video / audio reproducing unit is provided, the discriminating means is not included in the video / audio reproducing unit, and the cost of the video / audio reproducing unit can be kept low.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic structure of a disk reproducing device 31 according to an embodiment of the present invention, FIG. 2 is a block diagram showing the specific structure of the disk reproducing device 31, and FIG. 3 is a disk of a prior art. FIG. 9 is a block diagram of the playback device 25. 31 …… Disk playback device, 32 …… Compact disk player, 34a, 34b …… Amplification circuit, 35a, 35b …… Speaker,
38 …… decoder, 42 …… display control circuit, 43 …… key input device, 44 …… geomagnetic detector, 45 …… display device, 51 …… compact disk, 64 …… discrimination circuit, 84 …… data processing circuit

Claims (1)

[Claims] 1. A discriminating means for discriminating whether a signal read from a disk is a data signal, or at least one of a video signal and an audio signal, and a signal read from the disc for judging from the discriminating means. A video / audio reproduction unit that reproduces at least one of the video signal and the audio signal based on the output of the data processing unit, and a data processing unit that processes the data signal based on the output from the determination unit. A disk reproducing apparatus, wherein the discriminating means is provided in the data processing section.